
() was a common name for the fitting of an upward-firing
autocannon
An autocannon, automatic cannon or machine cannon is a automatic firearm, fully automatic gun that is capable of rapid-firing large-caliber ( or more) armour-piercing, explosive or incendiary ammunition, incendiary shell (projectile), shells, ...
or
machine gun, to an
interceptor
Interceptor may refer to:
Arts and entertainment
Film and television
* ''The Interceptor'', a British drama series on BBC One
* Interceptor (game show), ''Interceptor'' (game show), a British television game show that ran during 1989
* Interc ...
aircraft, such as a
night fighter
A night fighter (later known as all-weather fighter or all-weather interceptor post-Second World War) is a largely historical term for a fighter aircraft, fighter or interceptor aircraft adapted or designed for effective use at night, during pe ...
. The term was introduced by the
German
German(s) may refer to:
* Germany, the country of the Germans and German things
**Germania (Roman era)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizenship in Germany, see also Ge ...
during
World War II
World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...
. was previously a
German
German(s) may refer to:
* Germany, the country of the Germans and German things
**Germania (Roman era)
* Germans, citizens of Germany, people of German ancestry, or native speakers of the German language
** For citizenship in Germany, see also Ge ...
colloquialism
Colloquialism (also called ''colloquial language'', ''colloquial speech'', ''everyday language'', or ''general parlance'') is the linguistic style used for casual and informal communication. It is the most common form of speech in conversation amo ...
, meaning music that featured an unusual
tuning and/or
time signature
A time signature (also known as meter signature, metre signature, and measure signature) is an indication in music notation that specifies how many note values of a particular type fit into each measure ( bar). The time signature indicates th ...
(e.g.,
jazz
Jazz is a music genre that originated in the African-American communities of New Orleans, Louisiana, in the late 19th and early 20th centuries. Its roots are in blues, ragtime, European harmony, African rhythmic rituals, spirituals, h ...
). The standard usage of the adjective is often translated as "
slanting" or "
oblique
Oblique may refer to:
* an alternative name for the character usually called a slash (punctuation) ( / )
*Oblique angle, in geometry
* Oblique triangle, in geometry
* Oblique lattice, in geometry
* Oblique leaf base, a characteristic shape of the ...
", but its slang usage is often translated as "weird" or "strange".
The first such systems were developed (though not widely employed) in
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
as anti-
Zeppelin
A Zeppelin is a type of rigid airship named after the German inventor Ferdinand von Zeppelin () who pioneered rigid airship development at the beginning of the 20th century. Zeppelin's notions were first formulated in 1874Eckener 1938, pp. 155� ...
defenses by the French and British, in an era when fighters struggled to match the altitude capacity of the German airships and were forced to devise means to attack from below. The later resurrection of the concept by the Germans was inspired by observed weaknesses in the standard British
night bomber
A night bomber is a bomber aircraft intended specifically for carrying out bombing missions at night. The term is now mostly of historical significance. Night bombing began in World War I and was widespread during World War II. A number of moder ...
aircraft of the WW2 era (the
Avro Lancaster
The Avro Lancaster, commonly known as the Lancaster Bomber, is a British World War II, Second World War heavy bomber. It was designed and manufactured by Avro as a contemporary of the Handley Page Halifax, both bombers having been developed to ...
and
Handley Page Halifax
The Handley Page Halifax is a British Royal Air Force (RAF) four-engined heavy bomber of the Second World War. It was developed by Handley Page to the same specification as the contemporary twin-engine Avro Manchester.
The Halifax has its or ...
), which lacked ventral
ball turret
A ball turret is a spherical-shaped, altazimuth mount Aircraft gun turret, gun turret, fitted to some American-built aircraft during World War II. The name arose from the turret's spherical housing.
It was a manned turret, as distinct from remot ...
s in order to save weight, making them vulnerable to covert approaches and attacks from below under the cover of darkness. In keeping with the plans of the Allied
Combined Bomber Offensive
The Combined Bomber Offensive (CBO) was an Allied offensive of strategic bombing during World War II in Europe. The primary portion of the CBO was directed against Luftwaffe targets which were the highest priority from June 1943 to 1 April 1944. ...
, the American
B-17 Flying Fortress
The Boeing B-17 Flying Fortress is an American four-engined heavy bomber aircraft developed in the 1930s for the United States Army Air Corps (USAAC). A fast and high-flying bomber, the B-17 dropped more bombs than any other aircraft during ...
and
B-24 Liberator
The Consolidated B-24 Liberator is an American heavy bomber, designed by Consolidated Aircraft of San Diego, California. It was known within the company as the Model 32, and some initial production aircraft were laid down as export models desi ...
s operating in Europe (factory-equipped with ball turrets) typically bombed by day, thus experiencing far fewer encounters (and relative losses) from . Later similar Japanese experiments with upward-firing cannons on their night fighters in 1944 (intended to target the American
B-29 Superfortress
The Boeing B-29 Superfortress is a retired American four-engined Propeller (aeronautics), propeller-driven heavy bomber, designed by Boeing and flown primarily by the United States during World War II and the Korean War. Named in allusion to ...
fleet
firebombing Japan by night) were largely fruitless, owing to the B-29's notably superior speed and altitude.
In the initial stages of its operational use by German air crews, from mid-1943 to early 1944, many attacks using achieved complete surprise while destroying many British bombers. The crews that survived such attacks, during this period, often believed that damage and casualties had been caused by ground-based
anti-aircraft artillery
Anti-aircraft warfare (AAW) is the counter to aerial warfare and includes "all measures designed to nullify or reduce the effectiveness of hostile air action".AAP-6 It encompasses surface-based, subsurface (Submarine#Armament, submarine-lau ...
(AA or AAA), rather than fighters, and much confusion resulted until the cause was successfully pinpointed.
Background
World War I
During
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting to ...
,
pusher-configured fighter aircraft with flexibly-mounted forward-firing machine guns (especially the
Royal Aircraft Factory F.E.2s), enabled gunners to discover the principle of zero-deflection shooting. When firing upward at roughly a 45° elevation, when the attacking aircraft and its target are travelling at about the same speed and the range is fairly short, the trajectory will appear straight. The bullets' true path is a parabola, but the movement forward of both aircraft, and the air passing the aircraft counter the tendency of the round to arc down after leaving the muzzle so it appears to follow a straight line, simplifying accurate sighting which then requires no
deflection
Deflection or deflexion may refer to:
Board games
* Deflection (chess), a tactic that forces an opposing chess piece to leave a square
* Khet (game), formerly ''Deflexion'', an Egyptian-themed chess-like game using lasers
Mechanics
* Deflection ...
or leading of the target.

The pilots of
Royal Aircraft Factory B.E.2 night fighters, after trying various schemes for attacking the Zeppelin raiders of 1915–1916, hit on the idea of firing a mixture of explosive and incendiary bullets into the body of the airship ''from below''. For this purpose a
air-cooled Lewis gun was mounted in front of the pilot, firing upward. Exploitation of this led to the destruction of six German airships between September and December 1916. Later British night fighters were similarly armed with upward-firing guns.

Several
tractor-configured single-seat biplanes of the time featured machine guns mounted on the centre section of the top wing to fire over the radius of the propeller to bypass the need for
synchronization gear
A synchronization gear (also known as a gun synchronizer or interrupter gear) was a device enabling a single-engine tractor configuration aircraft to fire its forward-firing armament through the arc of its spinning Propeller (aeronautics), propel ...
s). Both the French mountings and the British
Foster mounting
The Foster mounting was a device fitted to some fighter aircraft of the Royal Flying Corps during the First World War. It was designed to enable a machine gun (in practice, a Lewis Gun) to fire ''over'', rather than ''through'' the arc of the spi ...
allowed a machine gun to be tipped back to reload and whether by accident or design, this allowed the gun to be held at an intermediate angle (ideally about 45°) and fired upward, steadying the gun and firing it with the "normal" trigger rather than the remote Bowden cable used for forward firing. These could then be used to attack enemy aircraft from the
blind spot below the tail. Most notable of the airplanes used were the
Nieuport 11
The Nieuport 11 (or Nieuport XI C.1 in contemporary sources), nicknamed the ''Bébé'', is a French World War I single seat sesquiplane fighter aircraft, designed by Gustave Delage. It was the primary aircraft that ended the Fokker Scourge in 1 ...
,
16 and
17 and 23 fighters from 1915 onwards, and the tactic was continued in British service, with the
Royal Aircraft Factory S.E.5s and
Sopwith Dolphin
The Sopwith 5F.1 Dolphin was a British fighter aircraft manufactured by the Sopwith Aviation Company. It was used by the Royal Flying Corps and its successor, the Royal Air Force, during the First World War. The Dolphin entered service on the ...
. That Dolphin entered service near the end of World War I, and was delivered with a pair of Lewis guns on a cross-tube connecting the upper wing spars. British
ace Albert Ball
Albert Ball, (14 August 1896 – 7 May 1917) was a British fighter pilot during the First World War. At the time of his death he was the United Kingdom's leading flying ace, with 44 victories, and remained its fourth-highest scorer b ...
in particular was a great exponent of this technique, The Germans copied the arrangement in 1917, when
Gerhard Fieseler of
''Jasta'' 38 attached two machine guns to an
Albatros D.V, pointing upwards and forwards.
Interwar years

The
Boulton Paul Bittern was a twin-engined night fighter (designed to
Specification
A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard.
There are different types of technical or engineering specificati ...
27/24) with an armament of barbette mounted guns, that could be angled upwards for attack against bombers, without having to enter a climb. The first of two Bittern prototypes flew in 1927, though performance was poor and the development stopped.

The
Westland C.O.W. Gun Fighter (1930) and
Vickers Type 161 (1931) were designed in response to Air Ministry specification F.29/27. This called for an interceptor fighter operating as a stable gun platform for the
Coventry Ordnance Works 37 mm autocannon produced by the Coventry Ordnance Works (COW).
The COW gun had been developed in 1918 for use in aircraft and had been tested on the Airco DH.4. The cannon fired shells and was to be mounted at 45 deg or more above the horizontal. The tactic was to fly below the target bomber or airship and fire upwards into it. Gun firing trials with both types went well, with no detriment to airframe or performance, although the Westland prototype displayed "alarming" handling characteristics. Neither the Type 161 nor its competitor, the Westland C.O.W. Gun Fighter were ordered, and no more was heard of this use of the aerial COW gun.
Similar logic lay behind the later Vickers Type 414 twin-engined fighter. This aircraft, which can be seen a natural successor to the Vickers COW gun fighter, combined a streamlined monoplane two-seater fighter airframe with a remotely controlled nose-mounted 40mm cannon that could be elevated for no-allowanc
shooting.

While turret fighters like the
Boulton Paul Defiant and the naval
Blackburn Roc addressed the same threat – enemy bombers attacking the UK – the approach was very different: upward-firing guns and no-allowance shooting are separate and distinct, and the equipment that can do the one can, generally speaking, be arranged so as to do the other (unless the fixed armament is automatically triggered, as in the photo-cell firing arrangements detailed below). On paper at least, the advantages of flexible aim and weight of fire from a two-seater were clear: the pilot is not overburdened, several fighters could be brought to bear on a target together, and there are two pairs of eyes per aircraft. However, the weight of a powered turret and air gunner imposed performance penalties.
The RAF put the Defiant into service in 1939, intending to use it against bombers, despite the bombers' numerous gun positions. However, the unexpected German territorial gains in France meant that bombers were escorted by fighters. Despite being utterly outclassed as a day fighter, when moved to the night-fighter role it had some success, typically attacking from below and slightly ahead of the bomber, well outside its field of defensive fire.
[Mondey 2002, p. 41.]
Meanwhile, in the United States, the twin-engine
Bell YFM-1 Airacuda was designed as a "bomber-destroyer", touted as "a mobile anti-aircraft platform".
[Winchester 2005, p. 74.] Its armament included mainly forward-firing
M4 37mm cannon, with an accompanying gunner mounted in a forward compartment of each of the two engine
nacelle
A nacelle ( ) is a streamlined container for aircraft parts such as Aircraft engine, engines, fuel or equipment. When attached entirely outside the airframe, it is sometimes called a pod, in which case it is attached with a Hardpoint#Pylon, pylo ...
s. Theoretically, the cannon could be slewed, aimed and fired at an oblique angle but flight tests and operational evaluation, disproved the theory: the type proved troublesome and except for initial flight testing in 1937, where full armament was carried, the nacelle cannon armament and the accompanying gunner–loaders were eliminated in the final development aircraft.
[Norton 2008, p. 123.]
World War II
German developments
''
Oberleutnant
(English: First Lieutenant) is a senior lieutenant Officer (armed forces), officer rank in the German (language), German-speaking armed forces of Germany (Bundeswehr), the Austrian Armed Forces, and the Swiss Armed Forces. In Austria, ''Oberle ...
''
Rudolf Schoenert of 4./
NJG 2 decided to experiment with upward-firing guns in 1941 and began trying out upward-firing installations, amid scepticism from his superiors and fellow pilots.
[Aders 1979, p. 67.] The first installation was made late in 1942, in a
Dornier Do 17Z-10 that was also equipped with the early UHF-band version of the
FuG 202 ''Lichtenstein B/C'' radar. In July 1942, Schoenert discussed the results of his experiment with General
Josef Kammhuber, who authorized the conversion of three
Dornier Do 217J-1s, to add a vertical armament of four or six
MG 151
The ''Maschinengewehr'' (MG) 151 is a belt-fed autocannon for aircraft use, developed in Nazi Germany from 1934 to 1940 and produced by Waffenfabrik Mauser during World War II. It was originally produced in 15.1 mm caliber from 1940, with a ...
s. Further experiments were carried out by the Luftwaffe flight testing centre at
Tarnewitz on the Baltic Sea coast through 1942. An angle between 60° and 75° was found to give best results, allowing a target turning at 8°/sec to be kept in the gunsight.
Schönert was made CO of II./NJG 5, and an armourer serving with the ''Gruppe'', ''
Oberfeldwebel
(; OFw or OF) is the fourth highest non-commissioned officer (NCO) rank in German Army and German Air Force.
History
The rank was introduced first by the German Reichswehr in 1920. Preferable most experienced Protégée-NCO of the old ...
'' Mahle, developed a working arrangement with the unit's
Messerschmitt Bf 110
The Messerschmitt Bf 110, often known unofficially as the Me 110,Because it was built before ''Bayerische Flugzeugwerke'' became Messerschmitt AG in July 1938, the Bf 110 was never officially given the designation Me 110. is a twin-engined (de ...
s, mounting a pair of
MG FF/M cannon in the rear compartment of the upper fuselage, firing through twin holes in the canopy's glazing. Schönert used such a modified Bf 110 to shoot down a bomber in May 1943. From June 1943, an official conversion kit was produced for the
Junkers Ju 88
The Junkers Ju 88 is a twin-engined multirole combat aircraft designed and produced by the German aircraft manufacturer Junkers Aircraft and Motor Works. It was used extensively during the Second World War by the ''Luftwaffe'' and became one o ...
and Dornier Do 217N fighters.
Between August 1943 and the end of the year, Schönert achieved 18 kills with the new gun installation.
Before the introduction of ''Schräge Musik'' in 1943, the ''Nachtjagdgeschwadern'' (NJG, night fighter wings) were equipped with
heavy fighter
A heavy fighter is an historic category of fighter aircraft produced in the 1930s and 1940s, designed to carry heavier weapons or operate at longer ranges than light fighter aircraft. To achieve performance, most heavy fighters were twin-engine ...
s fitted with
radar
Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ...
in the nose and a combination of front-firing and defensive weapons.
In the standard interception, the fighter approached the target from the rear to get into a firing position, presenting the night fighter crew with a much smaller target, a problem compounded by the
Royal Air Force
The Royal Air Force (RAF) is the Air force, air and space force of the United Kingdom, British Overseas Territories and Crown Dependencies. It was formed towards the end of the World War I, First World War on 1 April 1918, on the merger of t ...
bombers (such as the
Whitley and
Wellington
Wellington is the capital city of New Zealand. It is located at the south-western tip of the North Island, between Cook Strait and the Remutaka Range. Wellington is the third-largest city in New Zealand (second largest in the North Island ...
medium bombers) first being fitted with twin-gun hydraulic tail turrets, later upgraded to four guns to fend off just such attacks.
While the small calibre made these tail turret guns less effective than hoped, rear-gunners also maintained a watch for fighters and the pilot would make evasive manoeuvres such as corkscrews. Night-fighter pilots developed a new tactic to avoid the turret guns: instead of approaching directly from the rear they would approach about below the bomber, pull up sharply and start firing when the nose of the bomber appeared in the gunsight. As the fighter slowed and the bomber passed over them, its wings were sprayed with cannon or machine gun rounds. While effective, this manoeuvre was difficult to perform, there was a risk of collision and, if the bomb load exploded, it could destroy the night fighter. Systems similar to the original ''Schräge Musik'', such as the ''Sondergerät 500'' or
''Jägerfaust'', were tested on day fighters and other airframes, with the largest-calibre upward-firing aerial ordnance in German service, based on the quintuple-launcher of the
21 cm Nebelwerfer infantry barrage rocket, the experimental
heavy-bomber based ''Grosszerstörer'' (heavy destroyer) also under test.
The ''Jägerfaust'' system, firing projectiles vertically into the lower sides of bombers, was triggered by an optical device as the pilot passed beneath the target. This was tested on the Fw 190, and was destined for installation in the
Messerschmitt Me 163
The Messerschmitt Me 163 Komet is a rocket-powered interceptor aircraft primarily designed and produced by the German aircraft manufacturer Messerschmitt. It is the only operational rocket-powered fighter aircraft in history as well as ...
B and the Me 262B. The definitive night fighter version of the
Messerschmitt Me 262
The Messerschmitt Me 262, nicknamed (German for "Swallow") in fighter versions, or ("Storm Bird") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that was designed and produced by the German aircraft manufacturer Messers ...
, the Me 262B-2, was also designed to carry such an installation but it did not work and was not used operationally. Trials with the Me 163 were promising, with six operational aircraft modified. On 10 April 1945, a Halifax bomber was shot down by Fritz Kelb flying a ''Jägerfaust''-equipped Me 163B, most probably from I. ''Gruppe''/
JG 400 operating from
Brandis, Germany.
As experimental aircraft were developed as night fighters, such as the
Horten Ho 229, a ''Schräge Musik'' system was incorporated from the start. The experimental Horten Ho 229 flying wing series was proposed for consideration, with a form of unusual upward-firing armament for testing on the V4 night fighter prototype, photoelectric fired vertically mounted rockets or
recoilless gun
A Recoilless rifle ( rifled), recoilless launcher ( smoothbore), or simply recoilless gun, sometimes abbreviated to "rr" or "RCL" (for ReCoilLess) is a type of lightweight artillery system or man-portable launcher that is designed to eject some ...
s, instead of cannon armament inspired by the ''Jagdfaust''.
["Hitler's Stealth Fighter Re-created."](_blank)
''National Geographic'', 25 June 2009. Retrieved: 30 September 2010.
Typical installations
*
Dornier Do 217N: 4 × 20 mm
MG 151/20
The ''Maschinengewehr'' (MG) 151 is a belt-fed autocannon for aircraft use, developed in Nazi Germany from 1934 to 1940 and produced by Waffenfabrik Mauser during World War II. It was originally produced in 15.1 mm caliber from 1940, with a ...
*
Focke-Wulf Fw 189
The Focke-Wulf Fw 189 ''Uhu'' (Owl) is a twin-engine twin-boom tactical Aerial reconnaissance, reconnaissance and Liaison aircraft, army cooperation aircraft designed and produced by the Germany, German aircraft manufacturer Focke-Wulf. It was o ...
: 1 × 20 mm MG151/20 (used mainly on Eastern Front)
*
Heinkel He 219: 2 × 30 mm MK 108
*
Junkers Ju 88
The Junkers Ju 88 is a twin-engined multirole combat aircraft designed and produced by the German aircraft manufacturer Junkers Aircraft and Motor Works. It was used extensively during the Second World War by the ''Luftwaffe'' and became one o ...
C/G: 2 × 20 mm MG 151/20
*
Junkers Ju 388J: 2 × 30 mm MK 108
*
Messerschmitt Bf 110
The Messerschmitt Bf 110, often known unofficially as the Me 110,Because it was built before ''Bayerische Flugzeugwerke'' became Messerschmitt AG in July 1938, the Bf 110 was never officially given the designation Me 110. is a twin-engined (de ...
G-4: 2 × 20 mm MG FF/M
*
Messerschmitt Me 262
The Messerschmitt Me 262, nicknamed (German for "Swallow") in fighter versions, or ("Storm Bird") in fighter-bomber versions, is a fighter aircraft and fighter-bomber that was designed and produced by the German aircraft manufacturer Messers ...
B-2: 2 × 30 mm MK 108 (proposal only, B-2 version never produced)
*
Focke-Wulf Ta 154: 2 × 30 mm MK 108
Method of sighting guns
In the Ju 88 G-6 night fighter, which was fast and manoeuvrable, the Revi 16N gunsight was modified to allow the pilot to aim at the target by placing a mirror above his head, parallel to a similar mirror placed behind the gunsight (where the eye would normally be), which was further to the rear, functioning together in the manner of a
periscope
A periscope is an instrument for observation over, around or through an object, obstacle or condition that prevents direct line-of-sight observation from an observer's current position.
In its simplest form, it consists of an outer case with ...
. The Ju 88 G-6 was guided into position from sighting and final approach by commands from the radar operator, with the pilot only taking over when visual contact was made just prior to firing.
Operational use
''Schräge Musik'' (or ''Schrägwaffen'', as it was also called) was first used operationally during
Operation Hydra (the first instance of the
Allied bombing of Peenemünde) on the night of 17/18 August 1943. Three waves of aircraft bombed the area, and a diversion on Berlin by RAF Mosquitoes attracted the main ''Luftwaffe'' fighter effort, which meant that only the last of the three waves was met by many night fighters. Number
5 Group and
6 Group in the third wave lost 29 of their 166 bombers, well over the 10 per cent losses considered "unsustainable". In this raid 40 aircraft were lost: 23 Lancasters, 15 Halifaxes and two
Short Stirlings.
Adoption of ''Schräge Musik'' began in late 1943 and by 1944, a third of all German night fighters carried upward-firing guns. ''Schräge Musik'' proved most successful in the
Jumo 213 powered Ju 88 G-6. An increasing number of these installations used the more powerful calibre, short-barrelled
MK 108 cannon, such as those fitted to the
Heinkel He 219, fully contained within the fuselage. By mid-1944, He 219 aircrew were critical of the MK 108 installation, because its low muzzle velocity and limited range, meant that the night fighter had to be close to the bomber to attack and be vulnerable to damage from debris. They demanded that either the MK 108s be removed and replaced by MG FF/Ms or the angle of the mounting be changed. Although He 219s continued to be delivered with the twin 30 mm mounted, these were removed by front line units. Using the ''Schräge Musik'' required precise timing and swift evasion; a fatally damaged bomber could fall on the night fighter if the fighter could not quickly turn away. The He 219 was particularly prone to this; its high
wing loading
In aerodynamics, wing loading is the total weight of an aircraft or flying animal divided by the area of its wing. The stalling speed, takeoff speed and landing speed of an aircraft are partly determined by its wing loading.
The faster an airc ...
left it at the edge of stalling speed when matching the Lancaster's cruising speed, and therefore quite unmaneuverable. The same was true to a lesser extent of other ''Luftwaffe'' types such as the Ju 88, which was considered quite a "hot ship" by its crews. This was also a problem during normal stern attacks at low closure rate, but it was even more exaggerated during ''Schräge Musik'' attacks, since the pilot could not even make use of the limited climb performance available at the edge of the flight envelope to avoid debris from the stricken target.
''Schräge Musik'' allowed German night fighters to attack undetected, using special ammunition with a faint glowing trail replacing the standard tracer, combined with a "lethal mixture of armour-piercing, explosive and incendiary ammunition". Approaching from below provided the night fighter crew with the advantage that the bomber crew could not see them against the dark ground or sky, yet allowed the German crew to see the silhouette of the aircraft before they attacked. The optimum target for the night fighter was the wing fuel tanks, not the fuselage or bomb bay, because of the risk that exploding bombs would damage the attacker. "To overcome some of the problems, many NJG pilots closed the range at a lower level, below the
Monica zone of coverage, until they could see the bomber above; then they pulled up into a climb with all front guns blazing. This demanded fine judgement, gave only a second or two of firing time and almost immediately brought the fighter up behind the bomber's tail turret.
''Schräge Musik'' produced devastating results, with its most successful deployment in the winter of 1943–1944. This was a time when Bomber Command losses became unsupportable: the RAF lost 78 of 823 bombers that attacked Leipzig on 19 February, and 96 of the 795 bombers that attacked Nuremberg on 30/31 March 1944. RAF Bomber Command was slow to react to the threat from ''Schräge Musik'', with no reports from shot-down crews reporting the new tactic; the sudden increase in bomber losses had often been attributed to flak. Reports from air gunners of German night fighters stalking their prey from below had appeared as early as 1943 but had been discounted. A myth developed among RAF Bomber Command crews that "scarecrow shells" were encountered over Germany. The phenomenon was thought to be "AA shells simulating an exploding four-engined bomber and designed to damage morale. In many cases these were actual 'kills' by Luftwaffe night fighters... It was not for many months that evidence of these deadly attacks was accepted."
A detailed analysis of the damage done to returning bombers clearly showed that the night fighters were firing from below. Defence against the attacks included mixing
de Havilland Mosquito
The de Havilland DH.98 Mosquito is a British twin-engined, multirole combat aircraft, introduced during the World War II, Second World War. Unusual in that its airframe was constructed mostly of wood, it was nicknamed the "Wooden Wonder", or " ...
night fighters into the bomber stream, to pick up radar emissions from the German night fighters.
[Gunston 2004, p. 98.] Wing Commander J. D. Pattinson of 429 "Bison" Squadron, recognized an unseen danger but to him, it "was all presumption, not fact". He ordered that the mid-upper turrets be removed and the "displaced gunner would lie on a mattress on the floor as an observer, looking through a perspex blister for night fighters coming up from below".
["Schräge Musik & The Wesseling Raid: 21/22 June 1944."](_blank)
''207 Squadron Royal Air Force Association.'' Retrieved: 30 September 2010. Some early Lancaster B. IIs had retained the FN.64 ventral turret but its sighting periscope provided an overly tight field of view that left the gunner blind, and the traverse speed was too slow, making it useless.
A small number of Halifax and Lancaster bombers were fitted with a machine-gun mounted to fire through the hole where the turret would have been, normally of although Canadian units tended to use the machine gun. Initially these were unofficial, but Mod 925 provided an official modification in aircraft not equipped with
H2S bombing radar, which covered the turret location.
Even in the last year of the war, 18 months after the Peenemunde Raid, ''Schräge Musik'' night fighters were still taking a heavy toll, for example on the
Mitteland–
Ems Canal Raid, 21 February 1945,
Japan

In 1943, Commander
Yasuna Kozono of the 251st
Kōkūtai
A ''kōkūtai'' () was a military aviation unit in the Imperial Japanese Navy Air Service (IJNAS), similar to the Group (military aviation unit), air groups in other air arms and services of the time. Some comparable units included ''wing'' in th ...
, Imperial Japanese Navy in Rabaul came up with the idea of converting the
Nakajima J1N
The is a twin-engine aircraft used by the Imperial Japanese Navy during World War II. A prototype first flew in May 1941. The first full production variant of the ''Gekkō'', the J1N1-C was a reconnaissance aircraft, although many of these under ...
(J1N1-C) ''Irving'' into a night fighter. On 21 May 1943, at about the same time as the Luftwaffe's ''Oberleutnant'' Schoenert had his first victory with ''Schräge Musik'' in Europe, the field-modified J1N1-C KAI shot down two B-17s of the 43rd Bomb Group who were attacking air bases around Rabaul. The Navy took immediate notice and placed orders with Nakajima, for the newly designated J1N1-S night fighter design. This model was christened the Model 11 Gekkō (月光, Moonlight). It required only two crew and like the KAI, had a -calibre twinned pair of
Type 99 Model 1 cannon firing upward and a second pair firing downward at a forward 30° angle, also placed in the fuselage behind the cabin. The Type 99 20mm calibre autocannon ordnance used by Japanese aircraft was based on the drum-magazine fed Swiss
Oerlikon FF ordnance which was itself the basis for the Germans' own MG FF weapon, used to pioneer ''Schräge Musik'' for the Luftwaffe.
The Japanese Army Air Force
Mitsubishi Ki-46 "Dinah" twin engined fighter was used to test the ''Schräge Musik'' armament format in its Ki-46 III KAI version in June 1943, using a 37 mm
Ho-203 cannon with 200 rounds of ammunition, the largest calibre autocannon used for Schräge Musik-type operations. It was mounted in a similar position in the fuselage as the Luftwaffe's night fighters. Operational deployment began in October 1944.
One of the main Japanese fighters using this device was the
Kawasaki Ki-45 "Nick". With the ''Schräge Musik'' installation on the Nakajima J1N1-S "Gekkō" (two or three 20mm cannons firing upwards, some had two firing downwards), the
Nakajima C6N1-S "Myrt" single-engined, high-speed reconnaissance aircraft was used with a pair of 20 mm Type 99 cannons.
One variant of the common
A6M5 Zero single-seat fighter had a 20mm Type 99 cannon mounted just behind the pilot, firing upwards for night fighter combat.
United Kingdom

Air Ministry Specification F.9/37 led to the second,
Rolls-Royce Peregrine powered, prototype of the
Gloster G39 having its armament installed at an angle of +12° for 'no-allowance' firing – three dorsal 20mm cannon in the fuselage and two in the nose.
While it was a promising aircraft in its own right, by the time that the second prototype was completed the conventionally-armed
Bristol Beaufighter
The Bristol Type 156 Beaufighter (often called the Beau) is a British multi-role aircraft developed during the Second World War by the Bristol Aeroplane Company. It was originally conceived as a heavy fighter variant of the Bristol Beaufor ...
was already in production, so neither the G39 nor the subsequent
Gloster Reaper were pursued. Similar logic lay behind Air Ministry specification F11/37, which specified a turret-mounted cannon armament: of three companies who tendered (
Armstrong Whitworth
Sir W G Armstrong Whitworth & Co Ltd was a major British manufacturing company of the early years of the 20th century. With headquarters in Elswick, Tyne and Wear, Elswick, Newcastle upon Tyne, Armstrong Whitworth built armaments, ships, locomot ...
and
Bristol
Bristol () is a City status in the United Kingdom, cathedral city, unitary authority area and ceremonial county in South West England, the most populous city in the region. Built around the River Avon, Bristol, River Avon, it is bordered by t ...
) had turrets that could only traverse through the forward hemisphere, as did Air Ministry specification F22/39, written around the Vickers Type 414 twin-engined fighter, which combined a streamlined monoplane two-seater fighter airframe with a remotely controlled 40mm cannon in the nose that could be elevated for no-allowance shooting.

The Boulton Paul Defiant "turret fighter" was originally conceived under the F.9/35 specification for a "two-seat day and night fighter" to defend Great Britain against massed formations of unescorted enemy bombers.
[Buttler 2004, p. 51.] Regardless of the requirement, the use of its dorsal turret was based on the "broadside" fighter interception and combined fighter attack tactic of bomber interception. Attempts to take on single-seat fighters with Defiants led to catastrophic results in 1940 over France and during the
Battle of Britain
The Battle of Britain () was a military campaign of the Second World War, in which the Royal Air Force (RAF) and the Fleet Air Arm (FAA) of the Royal Navy defended the United Kingdom (UK) against large-scale attacks by Nazi Germany's air force ...
. With such high losses in day operations, the Defiant was transferred to night fighting and there the type achieved some success. Defiant night fighters typically attacked enemy bombers from below, in a similar manoeuvre to the later German ''Schräge Musik'' attacks, more often from slightly ahead or to one side, rather than from directly under the tail. During the ''
Blitz'' on
London
London is the Capital city, capital and List of urban areas in the United Kingdom, largest city of both England and the United Kingdom, with a population of in . London metropolitan area, Its wider metropolitan area is the largest in Wester ...
of 1940–1941, the Defiant equipped four squadrons, shooting down more enemy aircraft than any other type. The Defiant Mk II was fitted with
AI.IV radar and a Merlin XX engine. A total of 207 Defiant Mk IIs were built but the Defiant was retired as radar-equipped Beaufighter and Mosquito night fighters entered service in 1941 and 1942. Turret fighters with four 20mm cannon were specified under F.11/37 but got no further than
a scaled prototype.
A
Douglas Havoc, ''
BD126'', was fitted with six upward-firing machine guns in the fuselage behind the cockpit. The guns could be controlled in elevation from 30–50 degrees and 15 degrees in the azimuth by the gunner in the nose. The aircraft was tested at the
A&AEE in 1941 and then by the GRU and Fighter Interception Unit.
United States

The American
Northrop P-61 Black Widow night fighter could deliver a ''Schräge Musik''-like surprise of its own, because of the design of its
remote dorsal turret carrying a quartet of .50 caliber
Browning M2 machine guns, that could elevate to a full 90° position.
Post-war developments
The
Northrop F-89 Scorpion
The Northrop F-89 Scorpion is an night fighter, all-weather, twin-engined interceptor aircraft designed and produced by the American aircraft manufacturer Northrop Corporation. It was the first jet propulsion, jet-powered aircraft to be design ...
was originally designed to meet the 1945
United States Army Air Forces
The United States Army Air Forces (USAAF or AAF) was the major land-based aerial warfare service component of the United States Army and ''de facto'' aerial warfare service branch of the United States during and immediately after World War II ...
Army Air Technical Service Command specification ("Military Characteristics for All-Weather Fighting Aircraft") for a jet-powered night fighter to replace the P-61 Black Widow. The N-24 company proposal was armed with four 20 mm (.79 in) cannon in a unique trainable nose
turret
Turret may refer to:
* Turret (architecture), a small tower that projects above the wall of a building
* Gun turret, a mechanism of a projectile-firing weapon
* Optical microscope#Objective turret (revolver or revolving nose piece), Objective turre ...
that could rotate 360˚ with the guns able to elevate to 105˚.
[Davis and Menard 1990, pp. 4–5.] Ultimately, the F-89 design abandoned the swiveling nose turret in favor of a more standard front-firing cannon arrangement. A similar design – with .50 caliber machine guns – would also be tested on a United States Navy
Grumman F9F Panther.
In 1947, the
United States Air Force
The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...
tested a ''Schräge Musik'' gun installation on a
Lockheed F-80A Shooting Star standard "day fighter" aircraft (s/n 44-85044) to study the ability to attack Soviet bombers from below. Twin 0.5 in (12.7 mm) machine guns were fixed in an oblique mount.
A final attempt to exploit a fully traversing turret was found in the original 1948 design of the
Curtiss-Wright XF-87 Blackhawk all-weather jet fighter interceptor. Armament was to be a nose-mounted, powered turret containing four 20 mm (.79 in) cannon, but this installation was only fitted to the mock-up and never incorporated in the two prototypes.
In the Soviet Union the concept lasted slightly longer, with elevatable guns being tested on a
Mikoyan MiG-17 in the early 1950s.
Analysis
Freeman Dyson
Freeman John Dyson (15 December 1923 – 28 February 2020) was a British-American theoretical physics, theoretical physicist and mathematician known for his works in quantum field theory, astrophysics, random matrix, random matrices, math ...
, who was an analyst for
Operations research
Operations research () (U.S. Air Force Specialty Code: Operations Analysis), often shortened to the initialism OR, is a branch of applied mathematics that deals with the development and application of analytical methods to improve management and ...
of
RAF Bomber Command
RAF Bomber Command controlled the Royal Air Force's bomber forces from 1936 to 1968. Along with the United States Army Air Forces, it played the central role in the Strategic bombing during World War II#Europe, strategic bombing of Germany in W ...
in World War II, commented on the effectiveness of ''Schräge Musik'':
See also
*
Bomber destroyer
Bomber destroyers were World War II interceptor aircraft intended to destroy enemy bomber aircraft. Bomber destroyers were typically larger and heavier than general interceptors, designed to mount more powerful armament, and often having twin en ...
*
Strategic bombing
Strategic bombing is a systematically organized and executed military attack from the air which can utilize strategic bombers, long- or medium-range missiles, or nuclear-armed fighter-bomber aircraft to attack targets deemed vital to the enemy' ...
*
List of aircraft weapons
This is a list of weapons (aircraft ordnance) carried by aircraft.
Guns
In World War I, aircraft were initially intended for aerial reconnaissance, however some pilots began to carry rifles in case they spotted enemy planes. Soon, planes were fi ...
References
Notes
Citations
Bibliography
* Aders, Gebhard. ''History of the German Night Fighter Force 1917–45''. London: Jane's Publishing Company, 1979. .
* Andrews, C.F. and E.B. Morgan'. ''Vickers Aircraft since 1908.'' London: Putnam, 2nd ed., 1988. .
* Boyne, Walt. "A Fighter for All Weather... Curtiss XP-87 Blackhawk." ''Wings,'' Vol. 5, No. 1, February 1975.
* Bowers, Peter W. "Junkers Ju 88: Demon in the Dark." ''Wings,'' Vol. 12, No. 2, August 1982.
* Bruce, J.M. ''Warplanes of the First World War, Volume Three: Fighters.'' London: Macdonald, 1969. .
* Buttler, Tony. ''British Secret Projects: Fighters & Bombers 1935–1950''. Hinckley, UK: Midland Publishing, 2004. .
* Bowyer, Michael J.F. "The Boulton Paul Defiant." ''Aircraft in Profile, Vol. 5''. London, Profile Publications Ltd., 1966.
* Davis, Larry and Dave Menard. ''F-89 Scorpion in action'' (Aircraft Number 104). Carrollton, Texas: Squadron/Signal Publications Inc., 1990. .
* Gunston, Bill. ''Night Fighters: A Development and Combat History.'' New York: Charles Scribner's Sons, 2004, First edition 1976. .
* Hastings, Sir Max. ''Bomber Command'' (Pan Grand Strategy Series). London: Pan Books, 1999. .
* Hinchliffe, Peter. ''Other Battle: Luftwaffe Night Aces vs. Bomber Command.'' Minneapolis, MN: Zenith Press, 1996. .
* James, Derek N. ''Westland Aircraft since 1915.'' London: Putnam, 1991. .
* Mason, Francis K. ''The Avro Lancaster.'' Bucks, UK: Ashton Publications Ltd., First edition 1989.
* Mason, Francis K. ''The British Fighter Since 1912.'' Annapolis, Maryland: Naval Institute Press, 1977. .
* Mason, Tim. ''The Secret Years: Flight Testing at Boscombe Down 1939–1945.'' Crowborough, UK: Hikoki Publications, 2010, First edition 1998. .
* Mondey, David. ''The Hamlyn Concise Guide to Axis Aircraft of World War II.'' London: Bounty Books, 2006. .
* Mondey, David. ''The Hamlyn Concise Guide to British Aircraft of World War II.'' London: Chancellor Press, 2002. .
* Norton, Bill. ''U.S. Experimental & Prototype Aircraft Projects: Fighters 1939–1945''. North Branch, Minnesota: Specialty Press, 2008. .
* "Scorpion with a Nuclear Sting: Northrop F-89". ''Air International,'' July 1988, Vol. 35, No. 1, pp. 44–50. Bromley, UK: Fine Scroll. ISSN 0306-5634.
* Scutts, Jerry. ''Mosquito in Action, Part 1.'' Carrollton, Texas: Squadron/Signal Publications Inc., 1993. .
* Taylor, James and Martin Davidson. ''Bomber Crew.'' London: Hodder & Stoughton Ltd, 2004. .
* Taylor, John W.R. "Boulton Paul Defiant." ''Combat Aircraft of the World from 1909 to the present''. New York: G.P. Putnam's Sons, 1969. .
* Thompson, Warren. ''P-61 Black Widow Units of World War 2'' (Osprey Combat Aircraft 8). Oxford, UK: Osprey, 1998. .
* Wilson, Kevin. ''Men Of Air: The Doomed Youth Of Bomber Command'' (Bomber War Trilogy 2). London: Phoenix, 2008. .
* Winchester, Jim. "Bell YFM-1 Airacuda". ''The World's Worst Aircraft.'' London: Amber Books, 2005. .
External links
Peter Spoden Luftwaffe Night Fighter ace demonstrates Schrage Musik
{{DEFAULTSORT:Schrage Musik
Aircraft guns